Amazon has some bosch hoses on sale until 8/29 for 20% off. Make sure you select Amazon as the seller and you'll see the discount on the last page of the checkout.
You'll need to swap out the tool end connector and install the Festool tool end connector, but I believe the vac end connector will work with your Festools (just doesn't rotate like Festool's).
35mm 5 meter non-antistatic hose $21 - 20%
https://www.amazon.com/Bosch-VAC005-5-Meter-Vacuum-Hose/dp/B0000AV78B/ref=sr_1_1?ie=UTF8&qid=1471639729&sr=8-1&keywords=bosch+35mm+hose
35mm 5 meter antistatic hose $85 - 20% (edit - this one has a different vac end connector, so you'll need both Festool connectors for this hose!)
https://www.amazon.com/Bosch-5-Meter-Anti-Static-Hose-35mm/dp/B0000AV79B/ref=sr_1_2?ie=UTF8&qid=1471639729&sr=8-2&keywords=bosch+35mm+hose
You'll need to swap out the tool end connector and install the Festool tool end connector, but I believe the vac end connector will work with your Festools (just doesn't rotate like Festool's).
35mm 5 meter non-antistatic hose $21 - 20%
https://www.amazon.com/Bosch-VAC005-5-Meter-Vacuum-Hose/dp/B0000AV78B/ref=sr_1_1?ie=UTF8&qid=1471639729&sr=8-1&keywords=bosch+35mm+hose
35mm 5 meter antistatic hose $85 - 20% (edit - this one has a different vac end connector, so you'll need both Festool connectors for this hose!)
https://www.amazon.com/Bosch-5-Meter-Anti-Static-Hose-35mm/dp/B0000AV79B/ref=sr_1_2?ie=UTF8&qid=1471639729&sr=8-2&keywords=bosch+35mm+hose